Evaluation of Bioethanol Production from Enset (Ensete ventricosum (Welw.) Cheesman) Processing Waste and Leaf Using Saccharomyces cerevisiae

The depletion of fossil fuel reserves and the increasing awareness of greenhouse gas emissions act as the primary driving force for finding alternative renewable energy sources, especially those derived from biomass. This study was conducted with the objective of bio-ethanol production from non- edible plant biomass, Enset [Ensete ventricosum (Welw.) Cheesman] processing waste and leaves in batch fermentation using yeas (S. cerevisiae). Forty grams of acid pre-treated or untreated ensete processing waste and leaves were incubated with 1% of yeast under three different temperature (26°C, 30°C and 40°C) treatments and allowed to ferment over 16 days. Yeast cell density, total reducing sugars and percent of ethanol was measured at 4 days interval spectrophotometrically beginning from the incubation period. Results showed that all measured parameters subsequently decrease with increasing days of fermentation in both acid pre-treated and untreated substrates. Acid pre-treated substrates resulted in higher amounts of cell density, total reducing sugars and bio-ethanol than untreated substrates. Among the different temperatures, 30°C produced more bio-ethanol than others throughout the fermentation periods, and the result was in agreement with cell density and total sugars measured. In conclusion, this study showed that Enset processing waste and leaves can be used as a feedstock for bio-ethanol production and the yield can be increased with acid pre-treatment and incubation under 30°C temperature.